Method for forming a capacitor dielectric and method for manufacturing capacitor using the capacitor dielectric

ABSTRACT

A method for forming a capacitor dielectric includes depositing a zirconium oxide layer, performing a post-treatment on the zirconium oxide layer such that the zirconium oxide layer has a tetragonal phase, and depositing a tantalum oxide layer over the zirconium oxide layer such that the tantalum oxide layer has a tetragonal phase.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention claims priority to Korean patent applicationnumber 10-2006-0059998, filed on Jun. 29, 2006 which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a method for manufacturing asemiconductor device; and, more particularly, to a method for forming acapacitor dielectric having a zirconium oxide layer and a tantalum oxidelayer, and a method for manufacturing a capacitor using the capacitordielectric.

A stacked structure of hafnium oxide (HfO₂)/aluminum oxide(Al₂O₃)/hafnium oxide is conventionally used as a capacitor dielectricin a metal-insulator-metal (MIM) capacitor for enhancing capacitance andminimizing leakage current. Hafnium oxide is a high-dielectric-constantmaterial with a crystalline phase, and aluminum oxide is alow-dielectric-constant material with an amorphous phase.

FIG. 1 is a cross-sectional view of a conventional capacitor structure.The conventional capacitor includes a lower electrode 11, a capacitordielectric 12 having a stacked structure of HfO₂/Al₂O₃/HfO₂ disposed onthe lower electrode 11, and an upper electrode 13 disposed on thecapacitor dielectric 12.

Hafnium oxide increases the dielectric constant in the capacitordielectric 12. However, the leakage current performance characteristicdeteriorates when hafnium oxide crystallizes. Thus, the hafnium oxideshould be cautiously crystallized in the conventional capacitorstructure to achieve a favorable leakage current performancecharacteristic.

Furthermore, an amount by which the capacitance may be increased may belimited when using hafnium oxide for the capacitor dielectric. Hence,applying hafnium oxide to the capacitor dielectric is difficult when thedesign rule of the capacitor is reduced.

SUMMARY OF THE INVENTION

Specific embodiments of the present invention provide a method forforming a capacitor dielectric having a zirconium oxide layer and atantalum oxide layer. Both the zirconium oxide layer and the tantalumoxide layer have a tetragonal phase. The resulting capacitor dielectricmaintains a favorable leakage current performance characteristic and ahigh dielectric constant. A method for manufacturing a capacitor usingthe disclosed capacitor dielectric is also provided.

In accordance with an aspect of the present invention, a method forforming a capacitor dielectric includes depositing a zirconium oxidelayer. A post-treatment is performed on the zirconium layer such thatthe zirconium oxide layer has a tetragonal phase. A tantalum oxide layerhaving a tetragonal phase is deposited over the zirconium oxide layer.

In accordance with another aspect of the present invention, a method forforming a capacitor dielectric includes depositing a tantalum oxidelayer. A post-treatment is performed on the tantalum oxide layer suchthat the tantalum oxide layer has a tetragonal phase. A zirconium oxidelayer having a tetragonal phase is deposited over the tantalum oxidelayer.

In accordance with another aspect of the present invention, a method formanufacturing a capacitor includes forming a lower electrode. Acapacitor dielectric is formed over the lower electrode. The capacitordielectric includes a zirconium oxide layer having a tetragonal phaseand a tantalum oxide layer having a tetragonal phase. An upper electrodeis formed over the capacitor dielectric.

In accordance with another aspect of the present invention, a capacitorcomprises a lower electrode. A capacitor dielectric is formed over thelower electrode, wherein the capacitor dielectric includes a zirconiumoxide layer having a tetragonal phase and a tantalum oxide layer havinga tetragonal phase. An upper electrode is formed over the capacitordielectric.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a conventional capacitor structure.

FIG. 2 is a cross-sectional view of a capacitor structure in accordancewith a first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a capacitor structure in accordancewith a second embodiment of the present invention.

FIGS. 4A to 4C illustrate a method for manufacturing the capacitoraccording to the first embodiment of the present invention.

FIGS. 5A to 5C illustrate a method for manufacturing the capacitoraccording to the second embodiment of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

FIG. 2 illustrates a cross-sectional view of a capacitor structure inaccordance with a first embodiment of the present invention. A capacitorin accordance with the first embodiment includes a lower electrode 21, acapacitor dielectric 100 disposed on the lower electrode 21, and anupper electrode 24 disposed on the capacitor dielectric 100. Thecapacitor dielectric 100 includes a zirconium oxide (ZrO₂) layer 22A eand a tantalum oxide layer (Ta₂O₅) 23. The zirconium oxide layer 22A andthe tantalum oxide layer 23 are sequentially stacked on the lowerelectrode 21.

FIG. 3 is a cross-sectional view of a capacitor structure in accordancewith a second embodiment of the present invention. A capacitor inaccordance with the second embodiment includes a lower electrode 31, acapacitor dielectric 200 disposed on the lower electrode 31, and anupper electrode 34 disposed on the capacitor dielectric 200. Thecapacitor dielectric 200 is configured with a tantalum oxide layer 32Aand a zirconium oxide layer 33. The tantalum oxide layer 32A and thezirconium oxide layer 33 are sequentially stacked on the lower electrode31.

In FIGS. 2 and 3, both the zirconium oxide layers 22A and 33 and thetantalum oxide layers 23 and 32A that are used for each capacitordielectric 100 and 200 have a tetragonal phase. Thus, the zirconiumoxide layer 22A and 33 and the tantalum oxide layer 23 and 32A arerepresented as reference symbols T-ZrO₂ and T-Ta₂O₅, respectively.

An atomic layer deposition process is performed to obtain the tetragonalphase. The tetragonal phase may be obtained using ozone (O₃) treatmentbetween two deposition processes for the zirconium oxide and thetantalum oxide layers. A method for forming the capacitor dielectric isdescribed in detail below.

The lower electrodes 21 and 31 and the upper electrodes 24 and 34 eachinclude a metal electrode. Each electrode is formed of one materialselected from the group consisting of: titanium nitride (TiN), ruthenium(Ru), platinum (Pt), iridium (Ir) and hafnium nitride (HfN).

FIGS. 4A to 4C illustrate a method for manufacturing the capacitoraccording to the first embodiment of the present invention. Referring toFIG. 4A, the lower electrode 21 is formed. The lower electrode 21includes a metal electrode. Specifically, the lower electrode is formedof one material selected from the group consisting of: TiN, Ru, Pt, Irand HfN. The surface of the lower electrode 21 is cleaned using fluoricacid or buffered oxide etchant.

A wafer formed with the lower electrode 21 is loaded into a chamber inwhich an atomic layer deposition process will be performed. Thedeposition of the zirconium oxide layer 22 is performed under a chamberpressure of approximately 0.1 torr to approximately 10 torr, and at aprocess temperature of approximately 250° C. to approximately 350° C.

The atomic layer deposition process is performed repeatedly until thezirconium oxide layer 22 has a desired predetermined thickness.Specifically, the atomic layer deposition process is performed byrepeating a unit deposition cycle. The unit deposition cycle includes:loading the substrate with the lower electrode 21 into the depositionchamber; introducing a zirconium source; introducing a purge gas;introducing a reactant; and introducing a purge gas again.

After loading the substrate into the deposition chamber, the zirconiumsource is introduced into the chamber so that it is adsorbed on thelower electrode 21. The zirconium source uses a precursor selected fromthe group consisting of: Zr[NC₂H₅CH₃]₄], Zr[OC(CH₃)₂CH₂OCH₃]₄,Zr[OC(CH₃)₃]₄, ZrCl₄ and ZrI₄. The zirconium source flows forapproximately 0.1 to 10 seconds.

The purge gas is introduced into the deposition chamber to remove anyunreacted zirconium source from the deposition chamber that was notadsorbed on the surface of the lower electrode. Inert gas (e.g., Ar, He,N₂ gas or the like, and combinations thereof) is used as the purge gas.The purge gas flows for approximately 0.1 to 10 seconds.

The reactant is introduced into the deposition chamber. The reactant mayinclude O₃ or O₂ plasma. The reactant flows for approximately 0.1 to 10seconds.

The purge gas is introduced into the deposition chamber again to removeany unreacted reactant and any by-products. The inert gas is used as thepurge gas, and the purge gas flows for approximately 0.1 to 10 seconds.

By repeating the unit deposition cycle described above, the zirconiumoxide layer is deposited on the lower electrode 21 at a desiredthickness. In one embodiment, the desired thickness is fromapproximately 40 Å to approximately 100 Å

Referring to FIG. 4B, after depositing the zirconium oxide layer 22, anozone treatment is performed on the zirconium oxide layer 22 so that thezirconium oxide layer 22 has a tetragonal phase. The ozone treatment isperformed at a process temperature of approximately 300° C. toapproximately 500° C. In addition, the ozone concentration isapproximately 180 g/m³ to approximately 300 g/m³. Hereinafter, thezirconium oxide layer 22 with the tetragonal phase is referred to as aT-zirconium oxide layer (T-ZrO₂) 22A.

Referring to FIG. 4C, a tantalum oxide layer 23 is deposited on theT-zirconium oxide layer 22A. The tantalum oxide layer 23 has a thicknessof approximately 20 Å to approximately 100 Å using the atomic layerdeposition process described above. The atomic layer deposition processis performed at a chamber pressure of approximately 0.1 torr toapproximately 10 torr, and at a process temperature of approximately250° C. to approximately 350° C. A deposition method of the tantalumoxide layer 23 is described in detail below.

The atomic layer deposition process is performed repeatedly until thetantalum oxide layer 23 has a desired predetermined thickness.Specifically, the atomic layer deposition process is performed byrepeating a unit deposition cycle in a deposition chamber. The unitdeposition cycle includes: introducing tantalum source onto thesubstrate on which the T-zirconium oxide layer 22A is formed;introducing a purge gas; introducing a reactant; and introducing a purgegas again.

The tantalum source is introduced into the deposition chamber to beadsorbed on the T-zirconium oxide layer 22A. The tantalum source uses aprecursor of tantalum chloride (TaCl₅). The tantalum source flows forapproximately 0.1 to 10 seconds.

The purge gas is introduced into the deposition chamber to remove anyunreacted remaining tantalum source which is not adsorbed on the surfaceof the T-zirconium oxide layer 22A. Inert gas (e.g., Ar, He, N₂ gas orthe like, and combinations thereof) is used as the purge gas. The purgegas flows for approximately 0.1 to 10 seconds.

The reactant is introduced into the deposition chamber. The reactant mayinclude O₃ or O₂ plasma. The reactant flows for approximately 0.1 to 10seconds.

The purge gas is introduced into the deposition chamber again to removeany unreacted reactant and by-products. The inert gas is used as thepurge gas, and the purge gas flows for approximately 0.1 to 10 seconds.

By repeating the unit deposition cycle described above, the tantalumoxide layer 23 is deposited on the T-zirconium oxide layer 22A at adesired thickness. In one embodiment, the desired thickness is fromapproximately 20 Å to approximately 100 Å

When the tantalum oxide layer 23 is deposited as described above, thetantalum oxide layer 23 has a tetragonal phase. In other words, when thetantalum oxide layer 23 is deposited on the T-zirconium oxide layer 22Ahaving the tetragonal phase, the tantalum oxide layer 23 also has thetetragonal phase. Hereinafter, the tantalum oxide layer 23 with thetetragonal phase is referred to as a T-tantalum oxide layer (T-Ta₂O₅).

FIGS. 5A to 5C illustrate a method for manufacturing a capacitoraccording to the second embodiment of the present invention. Referringto FIG. 5A, the lower electrode 31 is formed. In one embodiment, thelower electrode 31 includes a metal. Specifically, the lower electrode31 is formed of one material selected from the group consisting of: TiN,Ru, Pt, Ir and HfN. The surface of the lower electrode 31 is cleanedusing fluoric acid or buffered oxide etchant.

A wafer that is formed with the lower electrode 31 is loaded into achamber in which an atomic layer deposition process will be performed.The deposition of the tantalum oxide layer 32 is performed at a chamberpressure of approximately 0.1 torr to approximately 10 torr, and at aprocess temperature of approximately 250° C. to approximately 350° C.

The tantalum oxide layer 32 is deposited on the lower electrode 31 at athickness of approximately 20 Å to approximately 100 Å using the atomiclayer deposition process. The atomic layer deposition process isperformed under a chamber pressure of approximately 0.1 torr toapproximately 10 torr and at a process temperature of approximately 250°C. to approximately 350° C. A deposition method of the tantalum oxidelayer 32 is described in detail below.

The atomic layer deposition process is performed repeatedly until thetantalum oxide layer 32 has a desired predetermined thickness.Specifically, the atomic layer deposition process is performed byrepeating a unit deposition cycle. The unit deposition cycle includes:introducing a tantalum source into the deposition chamber; introducing apurge gas; introducing a reactant; and introducing a purge gas again.

The tantalum source is introduced into the deposition chamber so thatthe tantalum source is adsorbed on the lower electrode 31. In oneembodiment, the tantalum source uses a precursor of tantalum chloride(TaCl₅). The tantalum source flows for approximately 0.1 to 10 seconds.

The purge gas is introduced into the deposition chamber to remove anyunreacted remaining tantalum source. The unreacted tantalum source mayinclude tantalum source that is not adsorbed on the surface of the lowerelectrode 31. Inert gas (e.g., Ar, He, N₂ gas, or the like, andcombinations thereof) is used as the purge gas. The purge gas flows forapproximately 0.1 to 10 seconds.

The reactant is introduced into the deposition chamber. The reactant mayinclude O₃ or O₂ plasma. The reactant flows for approximately 0.1 to 10seconds.

The purge gas is introduced into the deposition chamber again to removeany unreacted reactant and by-products. The inert gas is used as thepurge gas, and the purge gas flows for approximately 0.1 to 10second(s).

By repeating the unit deposition cycle, the tantalum oxide layer 32 isdeposited on the lower electrode 31 at a desired thickness. In oneembodiment, the desired thickness of the tantalum oxide layer 32 is fromapproximately 20 Å to approximately 100 Å

After depositing the tantalum oxide layer 32, ozone treatment isperformed to provide the tantalum oxide layer 32 with a tetragonalphase, as illustrated in FIG. 5B. In one embodiment, the ozone treatmentis performed at a process temperature of approximately 300° C. toapproximately 500° C. and at an ozone concentration of approximately 180g/m³ to approximately 300 g/m³. The tantalum oxide layer 32 is convertedinto the tantalum oxide with the tetragonal phase (T-Ta₂O₅) after theozone treatment.

Subsequently, referring to FIG. 5C, a zirconium oxide layer 33 isdeposited on the T-tantalum oxide layer 32A.

A deposition method of the zirconium oxide layer using the atomic layerdeposition process will be described. The atomic layer depositionprocess is performed repeatedly until the zirconium oxide layer has adesired predetermined thickness. Specifically, the atomic layerdeposition process is performed by repeating a unit deposition cycle.The unit deposition process includes: loading the substrate formed withthe T-tantalum oxide layer 32A into the deposition chamber; introducinga zirconium source; introducing a purge gas; introducing a reactant; andintroducing a purge gas again.

After loading the substrate into the deposition chamber, the zirconiumsource is introduced into the chamber so that it is adsorbed on theT-tantalum oxide layer 32A. In one embodiment, the zirconium source usesa precursor selected from the group consisting of: Zr[NC₂H₅CH₃]₄],Zr[OC(CH₃)₂CH₂OCH₃]₄, Zr[OC(CH₃)₃]₄, ZrCl₄ and ZrI₄. The zirconiumsource flows for approximately 0.1 to 10 seconds.

The purge gas is introduced into the deposition chamber to remove anyunreacted remaining zirconium source from the deposition chamber. Theunreacted zirconium source may include any zirconium source that is notadsorbed on the surface of the T-tantalum oxide layer 32A. Inert gas(e.g., Ar, He, N₂ gas or the like, and combinations thereof) is used asthe purge gas. The purge gas flows for approximately 0.1 to 10 seconds.

The reactant is introduced into the deposition chamber. The reactant mayinclude O₃ or O₂ plasma. The reactant flows for approximately 0.1 to 10seconds.

The purge gas is introduced into the deposition chamber again to removeany unreacted reactant and by-products. The inert gas is used as thepurge gas, and the purge gas flows for approximately 0.1 to 10 seconds.

By repeating the unit deposition cycle, the zirconium oxide layer 33 isdeposited on the T-tantalum oxide layer 32A at a desired thickness. Inone embodiment, the desired thickness of the zirconium oxide layer 33 isfrom approximately 40 Å to approximately 100 Å

When the zirconium oxide layer 33 is deposited as described above, thezirconium oxide layer 33 has a tetragonal phase. In other words, whenthe zirconium oxide layer 33 is deposited on the T-tantalum oxide layer32A having the tetragonal phase, the zirconium oxide layer 33 also hasthe tetragonal phase.

In the embodiments described, the deposition of the zirconium oxidelayer, the ozone treatment and the deposition of the tantalum oxidelayer are performed in situ.

In accordance with the embodiments described above, the capacitordielectric is configured as a bilayer with Ta₂O₅/ZrO₂ or ZrO₂/Ta₂O₅,instead of a multi-stacked layer such as a conventional triple layerwith HfO₂/Al₂O₃/HfO₂. In the present embodiments, a first dielectriclayer, i.e., the zirconium oxide layer (or tantalum oxide layer), isdeposited with a predetermined thickness. The ozone treatment isperformed to provide the first dielectric layer with the tetragonalphase. Subsequently, a second dielectric layer, i.e., the tantalum oxidelayer (or zirconium oxide layer), is deposited on the ozone-treatedfirst dielectric layer such that the second dielectric layer also hasthe tetragonal phase. In other words, by depositing the seconddielectric layer on the ozone-treated first dielectric layer with thetetragonal phase at a predetermined temperature, the second dielectriclayer is deposited with the tetragonal phase on the first dielectriclayer. For example, if the tantalum oxide layer is deposited on theT-zirconium oxide layer, the tantalum oxide layer formed on theT-zirconium oxide layer also has the tetragonal phase.

When both the zirconium oxide layer and the tantalum oxide layer havethe tetragonal phase, they provide better leakage current performancecharacteristic than the zirconium oxide and the tantalum oxide layers atother phases.

The dielectric constant of the zirconium oxide layer is nearly two timesgreater in the tetragonal phase than in a cubic phase. Specifically, thezirconium oxide layer has a dielectric constant of approximately 23 inthe cubic phase, but it has a dielectric constant of approximately 40 inthe tetragonal phase. Thus, the leakage current performancecharacteristic is enhanced.

Furthermore, it is possible to obtain a higher capacitance than theconventional capacitor dielectric. Similarly, the tantalum oxide layerhas a dielectric constant of approximately 20 in the amorphous phase,whereas it has a dielectric constant of approximately 25 toapproximately 50 during crystallization. Therefore, the capacitance ofthe tantalum oxide layer is improved.

When forming the capacitor dielectric by sequentially performing thedeposition of the first dielectric layer, the ozone treatment, and thedeposition of the second dielectric layer, the capacitor dielectrichaving the tetragonal phase can be formed by controlling the processtemperature and the deposition thickness of each dielectric layer. Thus,it is possible to form a capacitor dielectric that can provide highcapacitance as well as excellent leakage current performancecharacteristics.

As described above, in accordance with the present invention, thestacked structure of the zirconium oxide layer and the tantalum oxidelayer is used as the capacitor dielectric. The ozone treatment isperformed between two deposition processes so that both the zirconiumoxide layer and the tantalum oxide layer have the tetragonal phase. Thetetragonal phase enhances the leakage current performancecharacteristics and increases the capacitance.

In one embodiment, the stacked structure of the zirconium oxide layerand the tantalum oxide layer has an effective oxide thickness ofapproximately 9 Å or smaller due to a high dielectric constant.Accordingly, it is possible to secure sufficient capacitance even thougha design rule is reduced

While the present invention has been described with respect to specificembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from thespirit and scope of the invention as defined in the following claims.

1. A method for forming a capacitor dielectric, the method comprising:depositing a zirconium oxide layer over a substrate; performing apost-treatment on the zirconium oxide layer such that the zirconiumoxide layer has a tetragonal phase; and depositing a tantalum oxidelayer over the zirconium oxide layer such that the tantalum oxide layerhas a tetragonal phase.
 2. The method of claim 1, wherein thepost-treatment includes ozone treatment.
 3. The method of claim 1,wherein the post-treatment includes oxygen treatment that is performedat a temperature of approximately 300° C. to approximately 500° C. withan oxygen concentration ranging from approximately 180 g/m³ toapproximately 300 g/m³, the oxygen treatment involving a use of ozone.4. The method of claim 1, wherein depositing the zirconium oxide layerand depositing the tantalum oxide layer are performed using an atomiclayer deposition process.
 5. The method of claim 4, wherein the atomiclayer deposition process of the zirconium oxide layer is performed byrepeating a unit deposition cycle until the zirconium oxide layer has athickness ranging from approximately 40 Å to approximately 100 Å theunit deposition cycle comprising introducing a zirconium source,introducing a first purge gas, introducing a reactant, and introducing asecond purge gas.
 6. The method of claim 5, wherein the zirconium sourceuses a precursor selected from a group consisting of: Zr[NC₂H₅CH₃]₄],Zr[OC(CH₃)₂CH₂OCH₃]₄, Zr[OC(CH₃)₃]₄, ZrCl₄ and ZrI₄, and further whereinthe zirconium source flows for approximately 0.1 to 10 seconds, whereinthe first purge gas and the second purge gas are the same type.
 7. Themethod of claim 4, wherein the atomic layer deposition process of thetantalum oxide layer is performed by repeating a unit deposition cycleuntil the tantalum oxide layer has a thickness of approximately 20 Å toapproximately 100 Å the unit deposition cycle comprising introducing atantalum source, introducing a first purge gas, introducing a reactant,and introducing a second purge gas, wherein the first purge gas and thesecond purge gas are the same type.
 8. The method of claim 7, whereinthe tantalum source uses a precursor of tantalum chloride, and furtherwherein the tantalum source flows for approximately 0.1 to 10 seconds.9. The method of claim 5, wherein the reactant includes one of: O₃ andO₂ plasma.
 10. The method of claim 5, wherein the first purge gas andthe second purge gas each include an inert gas.
 11. The method of claim1, wherein depositing the zirconium oxide layer and depositing thetantalum oxide layer are performed at a temperature of approximately250° C. to approximately 350° C. and under a pressure of approximately0.1 torr to approximately 10 torr.
 12. The method of claim 1, whereindepositing the zirconium oxide layer, performing the post-treatment anddepositing the tantalum oxide layer are performed in situ.
 13. A methodfor forming a capacitor dielectric, the method comprising: depositing atantalum oxide layer over a substrate; performing a post-treatment onthe tantalum oxide layer to provide the tantalum oxide layer with atetragonal phase; and depositing a zirconium oxide layer over thetantalum oxide layer such that the zirconium oxide layer has atetragonal phase.
 14. The method of claim 13, wherein the post-treatmentinvolves a use of ozone.
 15. The method of claim 14, wherein thepost-treatment is performed at a temperature of approximately 300° C. toapproximately 500° C. in an environment with an oxygen concentration ofapproximately 180 g/m³ to approximately 300 g/m³.
 16. The method ofclaim 13, wherein depositing the tantalum oxide layer and depositing thezirconium oxide layer are performed using an atomic layer depositionprocess.
 17. The method of claim 16, wherein the atomic layer depositionprocess of the zirconium oxide layer is performed by repeating a unitdeposition cycle until the zirconium oxide layer has a thickness ofapproximately 40 Å to approximately 100 Å the unit deposition cyclecomprising introducing a zirconium source, introducing a first purgegas, introducing a reactant, and introducing a second purge gas.
 18. Themethod of claim 17, wherein the zirconium source uses a precursorselected from a group consisting of: Zr[NC₂H₅CH₃]₄],Zr[OC(CH₃)₂CH₂OCH₃]₄, Zr[OC(CH₃)₃]₄, ZrCl₄ and ZrI₄, and further whereinthe zirconium source flows for approximately 0.1 to 10 seconds.
 19. Themethod of claim 16, wherein the atomic layer deposition process of thetantalum oxide layer is performed by repeating a unit deposition cycleuntil the tantalum oxide layer has a thickness of approximately 20 Å toapproximately 100 Å the unit deposition cycle comprising: introducing atantalum source, introducing a first purge gas, introducing a reactant,and introducing a second purge gas.
 20. The method of claim 19, whereinthe tantalum source uses a precursor of tantalum chloride, and furtherwherein the tantalum source flows for approximately 0.1 to 10 seconds.21. The method of claim 19, wherein the reactant includes one of: O₃ andO₂ plasma.
 22. The method of claim 19, wherein the first purge gas andthe second purge gas each includes an inert gas.
 23. The method of claim19, wherein depositing the tantalum oxide layer and depositing thezirconium oxide layer are performed at a temperature of approximately250° C. to approximately 350° C. and under a pressure of approximately0.1 torr to approximately 10 torr.
 24. The method of claim 13, whereinthe depositing-a-tantalum-oxide-layer step, theperforming-a-post-treatment step, and thedepositing-a-zirconium-oxide-layer step are performed in situ.
 25. Amethod for manufacturing a capacitor, the method comprising: forming alower electrode over a substrate; forming a capacitor dielectric overthe lower electrode, wherein the capacitor dielectric includes azirconium oxide layer having a tetragonal phase and a tantalum oxidelayer having a tetragonal phase; and forming an upper electrode over thecapacitor dielectric.
 26. The method of claim 25, wherein forming thecapacitor dielectric comprises: depositing a zirconium oxide layer;performing a post-treatment on the zirconium oxide layer such that thezirconium oxide layer has a tetragonal phase; and depositing a tantalumoxide layer over the zirconium oxide layer such that the tantalum oxidelayer has a tetragonal phase.
 27. The method of claim 25, whereinforming the capacitor dielectric comprises: depositing a tantalum oxidelayer; performing a post-treatment on the tantalum oxide layer such thatthe tantalum oxide layer has a tetragonal phase; and depositing azirconium oxide layer over the tantalum oxide layer such that thezirconium oxide layer has a tetragonal phase.
 28. The method of claim26, wherein the post-treatment includes a use of ozone.
 29. The methodof claim 26, wherein the post-treatment includes use of oxygen, whereinthe treatment is performed at a temperature of approximately 300° C. toapproximately 500° C. in an environment with an oxygen concentration ofapproximately 180 g/m³ to approximately 300 g/m³.
 30. The method ofclaim 26, wherein depositing the zirconium oxide layer and depositingthe tantalum oxide layer are performed using an atomic layer depositionprocess.
 31. The method of claim 30, wherein the atomic layer depositionprocess of the zirconium oxide layer is performed by repeating a unitdeposition cycle until the zirconium oxide layer has a thickness ofapproximately 40 Å to approximately 100 Å the unit deposition cyclecomprising introducing a zirconium source, introducing a first purgegas, introducing a reactant, and introducing a second purge gas.
 32. Themethod of claim 31, wherein the zirconium source uses a precursorselected from a group consisting of: Zr[NC₂H₅CH₃]₄],Zr[OC(CH₃)₂CH₂OCH₃]₄, Zr[OC(CH₃)₃]₄, ZrCl₄ and ZrI₄, and further whereinthe zirconium source flows for approximately 0.1 to 10 seconds.
 33. Themethod of claim 30, wherein the atomic layer deposition process of thetantalum oxide layer is performed by repeating a unit deposition cycleuntil the tantalum oxide layer has a thickness of approximately 20 Å toapproximately 100 Å the unit deposition cycle comprising: introducing atantalum source, introducing a first purge gas, introducing a reactant,and introducing a second purge gas.
 34. The method of claim 33, whereinthe tantalum source uses a precursor of tantalum chloride, and furtherwherein the tantalum source flows for approximately 0.1 to 10 seconds.35. The method of claim 30, wherein depositing the zirconium oxide layerand depositing the tantalum oxide layer are performed at a temperaturerange of approximately 250° C. to approximately 350° C. and under apressure of approximately 0.1 torr to approximately 10 torr.
 36. Themethod of claim 26, wherein the depositing-a-tantalum-oxide-layer step,the performing-a-post-treatment step, and thedepositing-a-zirconium-oxide-layer step are performed in situ.
 37. Themethod of claim 27, wherein depositing the zirconium oxide layer anddepositing the tantalum oxide layer are performed using an atomic layerdeposition process.
 38. The method of claim 37, wherein the atomic layerdeposition process of the zirconium oxide layer is performed byrepeating a unit deposition cycle until the zirconium oxide layer has athickness of approximately 40 Å to approximately 100 Å the unitdeposition process comprising: introducing a zirconium source,introducing a first purge gas, introducing a reactant, and introducing asecond purge gas.
 39. The method of claim 38, wherein the zirconiumsource uses a precursor selected from a group consisting of:Zr[NC₂H₅CH₃]₄], Zr[OC(CH₃)₂CH₂OCH₃]₄, Zr[OC(CH₃)₃]₄, ZrCl₄ and ZrI₄, andfurther wherein the zirconium source flows for approximately 0.1 to 10seconds.
 40. The method of claim 37, wherein the atomic layer depositionprocess of the tantalum oxide layer is performed by repeating a unitdeposition cycle until the tantalum oxide layer has a thickness ofapproximately 20 Å to approximately 100 Å the unit deposition cyclecomprising: introducing a tantalum source, introducing a first purgegas, introducing a reactant, and introducing a second purge gas.
 41. Themethod of claim 40, wherein the tantalum source uses a precursor oftantalum chloride, and further wherein the tantalum source flows forapproximately 0.1 to 10 seconds.
 42. The method of claim 37, whereindepositing the zirconium oxide layer and depositing the tantalum oxidelayer are performed at a temperature of approximately 250° C. toapproximately 350° C. and under a pressure of approximately 0.1 torr toapproximately 10 torr.
 43. The method of claim 37, wherein thedepositing-a-tantalum-oxide-layer step, the performing-a-post-treatmentstep, and the depositing-a-zirconium-oxide-layer step are performed insitu.
 44. A capacitor comprising: a lower electrode; a capacitordielectric formed over the lower electrode, wherein the capacitordielectric includes a zirconium oxide layer having a tetragonal phaseand a tantalum oxide layer having a tetragonal phase; and an upperelectrode formed over the capacitor dielectric.